[U-Boot] [PATCH v4 3/4] generic board patch of manual reloc and zero gd_t

[FengHua]

> > 
> > > -----原始邮件-----
> > > 发件人: "Scott Wood" <scottwood at freescale.com>
> > > 发送时间: 2013年10月1日 星期二
> > > 收件人: FengHua <fenghua at phytium.com.cn>
> > > 抄送: "Simon Glass" <sjg at chromium.org>, trini <trini at ti.com>, u-boot <u-boot at lists.denx.de>
> > > 主题: Re: Re: [U-Boot] [PATCH v4 3/4] generic board patch of manual reloc and zero gd_t
> > > 
> > > On Tue, 2013-10-01 at 19:05 +0800, FengHua wrote:
> > > > How about place u-boot.bin at 0x90000000 and write a piece of code (elf format)
> > > > jumping from 0x80000000 to 0x90000000.
> > > 
> > > That seems even worse than converting the .bin back into an ELF...
> > >
> > Why? I could load u-boot.bin at 0x90000000 as data, I think it should works.
> > Or maybe secure state make the program jumping to secure memory.
> > so try switching to el2 before jumping.
> 
> It requires building another program image (even if it's a relatively
> simple one), as opposed to just invoking objcopy and ld, and it makes
> invoking the simulator more complicated.
Do not need to write a new program, just add the jumping code
immediately after setup_el3 of current aarch64-uboot,
it's the first booting program.
compile another u-boot without jumping code at 0x90000000,
it's the data.

> > > Do you know why loading the raw image at 0x80000000 isn't working?
> > The foundation model require a elf(axf) image being loaded, it use it to determine the entry point.  
> 
> Then why does it even try to start without an ELF being supplied (but
> won't try to start if I don't supply ELF *or* raw data)?
> Why is there no other way to supply an entry point (even just defaulting to the
> beginning of the raw image if no ELF is provided)?
Fast model for aarch64 support all of these. Maybe that's why Foundatiom model is free.

> Why does it fail when I supply *both* the ELF and the raw image, in either order?
The elf file will override the raw image if they are loaded at same address.

David